Syria and its ally Iran are threatening to retaliate against Israel for an airstrike carried out within Syrian borders.

U.S. officials said Israel launched the airstrike inside Syria on Wednesday, targeting a convoy believed to be carrying anti-aircraft weapons bound for Hezbollah, the powerful Lebanese militant group allied with Syria and Iran.

In response to the strike, Syrian Ambassador to Lebanon Ali Abdul-Karim Ali said Thursday that Damascus "has the option and the capacity to surprise in retaliation."

Abdul-Karim Ali said he could not predict when Damascus would retaliate, but told Hezbollah's al-Ahd news website that it was up to the relevant authorities to prepare the retaliation and choose the time and place.

In Iran, the country’s deputy foreign minister said on Press TV that the “strike on Syria will have serious consequences for Tel Aviv,” but did not elaborate, according to the Jerusalem Post.

Prior to the attack, last week, an aide to Iranian Supreme Leader Ayatollah Ali Khamenei told the Mehr news agency that any attack on Syria was an attack on itself, fearing that Iran and Iraq would be targeted next if Assad’s regime falls, Haaretz reports.